Fuel pump safety circuitry

ABSTRACT

VEHICLE CIRCUITRY HAVING PROVISIONS FOR INCREASING THE FUEL TRANSFER CAPABILITY OF A FUEL PUMP WHEN STARTING AN ENGINE. PREVENTING THE FUEL PUMP FROM TRANSFERRING FUEL TO THE ENGINE WHEN THE ENGINE IS FLOODED, OPERATNG THE FUEL PUMP AT A PLURALITY OF SPEEDS IN ACCORDANCE WITH THE ENGINE THROTTLE SETTING, ADVISING A VEHICLE OPERATOR THAT THE ENGINE OIL PRESSURE IN THE VEHICLE IS INSUFFICIENT TO PROPERLY LUBRICATE THE ENGINE BY ENERGIZING A TELLTALE NETWORK THAT IS NORMALY USED TO MONITOR VARIOUS OTHER CONDITIONS IN THE VEHICLE, STOPPING THE   ENGINE BY REMOVING ITS SUPPLY OF FUEL WHEN THE ENGINE LOSES OIL PRESSURE AND PERMITTING THE VEHICLE OPERATOR TO TEMPORARILY MAINTAIN THE SUPPLY OF FUEL TO THE ENGINE WHEN THE ENGINE LOSES OIL PRESSURE BY MANIPULATNG AN IGNITION SWITCH CHECKING THE OPERATIVENESS OF THE TELLTALE NETWORK BY COMPLETING CURRENT PATHS TO GROUND THROUGH A PLURALITY OF TELLTALES AND A GENERATOR FIELD WINDING WHEN THE ENGINE IS STOPPED AND THE IGNITION SWITCH IS IN AN ENGINE ON SETTING, AND ENERGIZING A GENERATOR TELLTALE WHEN A RECTIFIER IN A RECTIFIER NETWORK IS INOPERATIVE AND THE IGNITION SWITCH IS IN AN ENGINE OF SETTING.

United States Patent [72] lnventor Richard P. Ballou Howell, Mich. [21]Appl. No. 847,310 [22] Filed Aug. 4, 1969 [45] Patented June 28, 1971[73] Assignee General MotorsCorporation [54] FUEL PUMP SAFETY CIRCUITRY20 Claims, 2 Drawing Figs.

[52] U.S.Cl 123/136, 123/139, 123/179, 290/38 [51] Int. Cl. ..F02m 19/00[50] Field oISearch 123/32 (E), 102, 1 19, 136, 139.16, 139.17, 139.18,179 (A), 179 (B), 180, 198; 290/38; 307/10 [56] References Cited UNITEDSTATES PATENTS 2,311,179 2/1943 Berry 123/198 2,370,249 2/1945 Korte eta1. 123/179A 2,518,712 8/1950 Oversm. l23/179A 2,687,123 8/1954 Parsons.123/1403 3,476,949 11/1969 Ballou 290/38 Primary Examiner-Laurence M.Goodridge Attorneys-Jean L. Carpenter and Paul Fitzpatrick ABSTRACT:Vehicle circuitry having provisions for increasing the fuel transfercapability ofa fuel pump when starting an engine, preventing the fuelpump from transferring fuel to the engine when the engine is flooded,operating the fuel pump at a plurality of speeds in accordance with theengine throttle setting, advising a vehicle operator that the engine oilpressure in the vehicle is insufficient to properly lubricate the engineby energizing a telltale network that is normally used to monitorvarious other conditions in the vehicle, stopping the engine by removingits supply of fuel when the engine loses oil pressure and permitting thevehicle operator to temporarily maintain the supply of fuel to theengine when the engine loses oil pressure by manipulating an ignitionswitch, checking the operativeness of the telltale network by completingcurrent paths to ground through a plurality of telltales and a generatorfield winding when the engine is stopped and the ignition switch is inan engine on setting, and energizing a generator telltale when arectifier in a rectifier network is inoperative and the ignition switchis in an engine off setting.

TO CRANKING NETWORK TO IGNITION COIL CRANKING NETWORK FUEL PUMP SAFETYCIRCUITRY This invention relates to vehicle circuitry and in particularto circuitry for engine-driven vehicles.

Because the requirements of motor vehicles have undergone anevolutionary process in the last several years, due in part to manytechnological innovations, innumerable vehicle circuits have beendeveloped to provide various desired features. The circuits in commonuse, however, have been designed primarily with a view to achieving anew result and have thus been combined with existing circuits to thedetriment of overall efficiency The subject circuitry is thereforedirected both toward providing vehicle circuitry having new anddifferent features by enhancing the operation of components presentlyused in vehicle circuits and toward improving the overall design of thevehicle circuitry.

It is therefore an object of this invention to provide motor vehiclecircuitry having a provision for increasing the rate at which anelectric fuel pump transfers fuel to an engine in accordance with thesetting of the engine throttle so as to increase the fuel transfercapability of the fuel pump when the engine is to be operated at highspeeds.

It is also an object of this invention to provide vehicle circuitryhaving a provision for discontinuing the operation of an electric fuelpump in accordance with the engine throttle setting when starting aflooded engine.

A further object of this invention is to provide vehicle circuitryhaving a provision for stopping an engine by discontinuing the supply offuel to the engine when the engine oil pressure is insufficient toproperly lubricate the engine and for permitting the vehicle operator totemporarily maintain the supply of fuel to the engine by manipulation ofan ignition switch so as to temporarily continue the engine operation.

Another object of this invention is to provide vehicle circuitry havinga provision for warning of a loss of oil pressure and impending stoppageof an engine by energizing a telltale network that is normally used tomonitor various conditions in the vehicle other than the engine oilpressure.

It is an additional object of this invention to provide vehiclecircuitry having a provision for checking the operation of a pluralityof telltales that are normally used to monitor various conditions in thevehicle other than the operativeness of a generator by completing acurrent path to ground through the telltales and the field of thegenerator.

Itis another object of this invention to provide vehicle circuitryhaving a provision for energization of a voltage regulator coil directlyfrom the output of a generator so as to render the coil operationindependent of accessory loads in the vehicle.

It is also an object of this invention to provide vehicle circuitryhaving a provision for energizing the field of an enginedriven generatorthrough a switch responsive to oil pressure in the engine.

It is still another object of this invention to provide vehiclecircuitry having a provision for checking the presence of a shortedpositive diode in the rectifier of an AC generator by energizing a fieldrelay in a voltage regulator assembly so as to complete a current pathto ground through a generator operation telltale and an enginecontrolling switch that is placed in an engine off setting.

The foregoing and other objects and advantages of the invention willbecome apparent from the following description and from the accompanyingdrawings, in which FIG. I illustrates schematically a vehicle circuitincorporating the principles of the invention and FIG. 2 presents intable form the switching sequence of an ignition switch disclosed inFIG. 1.

As is seen in FIG. 1, the subject circuitry is comprised of an electricfuel pump for transferring fuel from a fuel reservoir (not shown) to anengine (not shown), a power source, shown as a battery 12, forenergizing the circuitry, an engine controlling switch 14 forcontrolling the energization of the circuitry by the battery 12, a pumpenergization network 16 for controlling the energization of the pump 10by the battery 12 in accordance with the setting of the enginecontrolling switch 14, a generator network 18 for recharging the battery12 when the engine is in operation, a generator telltale 20 forindicating a malfunction in the generator network 18, a telltale network22 for monitoring various conditions in the vehicle, and an engineresponsive switch 24 for controlling the energization of the pump 10,the telltale network 22, and the generator network 18 in accordance withthe engine operation.

While various conventional electric fuel pumps may be used as the pump10, the pump described in U.S. Pat. No. 3,418,991 to Shultz et al. issuggested as being suitable for use as the pump 10.

FIG. 1 also discloses how the subject circuitry may be combined withvarious other circuitry in a vehicle. For example, a set of terminals26, 28, 30 and 32 may be provided for energizing various accessory loadsfrom the battery 12 through the engine controlling switch 14. As personsskilled in the art will appreciate, the engine controlling switch 14 mayalso be used to control the operation of a cranking network (not shown)for starting the engine and an ignition coil (not shown) for providingthe engine with ignition energy.

The engine controlling switch 14 is an ignition switch which may be ofany conventional design, only its function being of concern to thisinvention. In the illustrated embodiment the ignition switch 14 has fourdistinct settings. These settings are ACC, OFF, ON, and START for engineOff with accessories On, engine Off with accessories Off, engine On withaccessories On, and engine Starting with accessories Off conditions,respectively.

The ignition switch 14 includes a set of grounded contacts 34 and 36 anda set of ungrounded contacts 38, 40, 42 and 44. The contacts 34, 36, 38,40, 42 and 44 are closed in accordance with the various enginecontrolling switch 14 settings as shown in FIG. 2. For example,referring to FIG. 2, when the ignition switch 14 is in the START settingonly the contacts 40, 42 and 44 are closed.

The pump energization network includes a starting branch 46 forenergizing the pump 10 when starting the engine and an operating branch48 for energizing the pump 10 when operating the engine. The startingbranch 46 includes a normally closed switch 50 responsive to the enginethrottle setting. Placing the ignition switch 14 in the START settingenergizes the pump 10 from the battery 12 through a current path thatincludes a lead 52, a junction block 54, a lead 56, the contacts 44, alead 58, the normally closed switch 50, a lead 60, and the pump 10. Thenormally closed switch 50 is adapted to be opened when the enginethrottle is fully opened, as when set for maximum engine speed, therebypreventing the pump 10 from transferring fuel to the engine so as tofacilitate starting the engine when the engine is flooded.

The operating branch 48 is energized in accordance with the setting ofthe ignition switch 14 and the position of the engine responsive switch24 so as to energize the pump 10 when the ignition switch 14 is in theON setting and the engine is in operation. While the engine responsiveswitch 24 may be responsive to several engine parameters, such as enginespeed and engine coolant pressure, the engine responsive switch 24 inthe illustrated embodiment is selected to be responsive to the engineoil pressure.

The operating branch 48 includes a voltage dropping resistor 62 and anormally open switch 64 that is responsive to the engine throttlesetting. When the ignition switch 14 is in the ON setting and the engineoperation has caused the oil pressure switch 24 to be closed a currentpath is completed from the battery 12 through the lead 52, the junctionblock 54, the lead 56, the contacts 38, a lead 66, the oil pressureswitch 24, a lead 68, a lead 70, a lead 72, the resistor 62, the lead60, and the pump 10.

When the engine is to be operated at high speeds it is desirable thatthe fuel transfer capability of the pump 10 be increased so as tofacilitate providing the engine with an increased quantity of fuel. Thisis achieved in the operating branch 48 by closing the normally openswitch 64 in response to the engine throttle setting. In operating theengine at low speeds the engine throttle setting is such that thenormally open switch 64 is open, causing the pump 10 to be energizedthrough the voltage dropping resistor 62, which is on the order of a 5ohm unit and which produces about a 4 voltage drop. When it is desiredto operate the engine at high speeds the engine throttle setting ischanged, closing the normally open switch 64 and bypassing the voltagedropping resistor 62 so as to increase the power supplied from thebattery 12 to the pump by applying virtually the entire battery 12voltage, usually about 12 volts, to the pump 10. The fuel transfercapability of the pump 10 is thus increased merely by changing theengine throttle setting. As persons skilled in the art will appreciate,a variable resistor may be used in place of the normally open switch 64to provide the pump 10 with several levels of energization dependentupon the engine throttle setting so as to more closely match the pump 10energization to the fuel consumption needs of the engine. The operatingbranch 48 will continue energization of the pump 10 in accordance withthe engine throttle setting so long as the oil pressure switch 24 andthe contacts 38 are closed.

The generator network 18 includes an engine-driven generator 74 forconverting mechanical energy supplied by the engine to electric energyand a voltage regulator assembly 76 for controlling the generator 74output. While the generator 74 may be of any conventional design, thegenerator 74 shown in the illustrated embodiment is the well-knowngenerator manufactured by the Delco-Remy Division of the General MotorsCorporation. The Delcotron includes a field winding 78 and a Y-connectedstator winding 80, comprised of individual windings 82, 84 and 86, thatcombine in a wellknown way to develop a three-phase AC output. TheDelcotron also includes a full wave bridge rectifier network 88,comprised of individual rectifiers 90, 92, 94, 96, 98 and 100, forchanging this three-phase output to a DC output, which is used torecharge the battery 12. The generator 74 output is supplied to thebattery 12 through a lead 102, the junction block 54, and the lead 52 soas to recharge the battery 12 when the engine is in operation.

The generator 74 output is dependent upon the energization of the fieldwinding 78, which is controlled by the voltage regulator assembly 76.The voltage regulator assembly 76 includes a voltage regulator 104 and afield relay 106. The voltage regulator 104 includes a voltage regulatorcoil 108, a fixed contact 110 and a pair of movable contacts 112 and114. The field relay 106 includes a relay winding 116, a pair of fixedcontacts 118 and 120 and a movable contact 122. The voltage regulatorassembly 76 also includes a current limiting resistor 124, the purposeof which will later become apparent.

The voltage regulator assembly 76 may be of several conventionaldesigns. The voltage regulator assembly 76 in the illustrated embodimentis the unit manufactured by the Deleo- Remy Division of the GeneralMotors Corporation under Part No. 1 l 195 I5. This unit has beenmodified for use in the illustrated embodiment by grounding the fixedcontact 118 and by providing for electrical separation of the voltagesensitive coil 108 from the movable contact 112 in a manner familiar toper sons skilled in the art.

The voltage regulator assembly 76 is powered by the battery 12 inaccordance with the ignition switch 14 setting and the engine oilpressure so as to be connected to the battery 12 when the ignitionswitch 14 is in the ON setting and the engine operation has closed theoil pressure switch 24. The voltage regulator assembly 76 is energizedthrough a current path from the battery 12 through the lead 52, thejunction block 54, the lead 56, thecontacts 38, the lead 66, the oilpressure switch 24, the lead 68, and a lead 126.

When the engine is in operation the voltage regulator assembly 76 isenergized and the generator 74 is driven by the engine so as to producean output from the stator winding 80 in accordance with the energizationof the field winding 78. The field winding 78 is initially energizedthrough a current path from the oil pressure switch 24 that includes thelead 68, the lead 126, a lead 128, the contacts 112 and 110, a lead 130,a lead 132, and the field winding 78. The battery 12 voltage is thusinitially supplied to the field winding 78.

As the generator 74 output increases the field relay 106 is energized bythe voltage produced at a junction 131 in the rectifier network 88, thejunction 131 being the R terminal on the Delcotron. Energization of thefield relay 106 causes the movable contact 122 to complete a circuitfrom the generator 74 through the lead 102, the junction block 54, alead 133, the contacts 120 and 122, and a lead 134 to the voltageregulator coil 108. So long as the output voltage from the generator 74that is applied to the voltage regulator coil 108 is below a certainpredetennined level the voltage regulator coil 108 is unable to separatethe contacts 110 and 112 and the field winding 78 continues to beenergized through the current path previously described.

When the generator 74 output exceeds the predetermined level the voltageregulator coil 108 separates the movable contact 112 from the fixedcontact 110, causing the fieldwinding 78 to be energized through thecurrent limiting resistor 124 that was previously bypassed by thecurrent path through the contacts 110 and 112. The current limitingresistor 124, which has a resistance of approximately 10 ohms, serves toreduce the energization of the field winding 78 so as to reduce thegenerator 74 output. As the generator 74 output is reduced to a levelslightly below the predetermined level the voltage regulator coil 108releases the movable contact 112, closing the contacts 110 and 112 so asto increase the energization of the field winding 78 as was previouslydescribed. in practice, the contacts 110 and 112 are opened and closedseveral times a second so as to maintain precise control of thegenerator 74 output voltage.

In the event the generator 74 output voltage exceeds a secondpredetermined level the voltage regulator coil 108 energization isincreased sufficiently to both separate the contacts 110 and 112 andclose the contacts 110 and 114. Since the movable contact 114 isgrounded, closing the contacts 110 and 114 grounds the field winding 78so as to rapidly reduce the generator 74 output voltage. As thegenerator 74 output voltage falls below the second predetermined levelthe contacts 110 and 114 are separated so as to permit partialenergization of the field winding 78 through the current limitingresistor 124 and the regulation of the generator 74 output continues inthe fashion previously discussed.

lt should be noted at this point that the provision for energizing thevoltage regulator coil 108 from the junction block 54 through thecontacts and 122 rather than through the ignition switch 14 provides avery important, though subtle, advantageous feature in the operation ofthe voltage regulator assembly 76. Since the voltage regulator coil 108is very sensitive to voltage variations, it should be isolated fromloads which produce transients, such as the accessory loads energizedfrom the lead 66. By connecting the voltage regulator coil 108 through arelatively direct route, i.e. with small lead wire and contactresistance, to the junction block 54 the voltage regulator coil 108 iseffectively rendered independent of the various accessory loads.

The generator telltale 20 is provided for indicating a ma]- function inthe generator network 18. Placing the ignition switch 14 in the ONsetting prior to starting the engine supplies the battery 12 voltage tothe generator telltale 20 through a current path that includes the lead52, the junction block 54, the lead 56, the contacts 40, and a lead 136.In addition, when the engine is not in operation the generator 74 is notproducing a voltage at the junction 131 so the field relay 106 isdeenergized and the contacts 118 and 122 are closed, grounding thegenerator telltale 20 through a lead 138, the lead 134, and the contacts122 and 118. Since virtually the entire battery 12 voltage is thusplaced across the generator telltale 20, the generator telltale 20 isenergized when the ignition switch 14 is in the ON setting and theengine is not in operation, providing a check of the generator telltale20 operativeness.

When the engine is in operation the generator 74 produces an output atthe junction 131, energizing the field relay 106 so as to close thecontacts 120 and 122. Closing the contacts 120 and 122 completes acurrent path from the generator 74 output through the lead 102, thejunction block 54, the lead 133, the contacts 120 and 122, the lead 134,and the lead 138 to the generator telltale 20. So long as the leads 136and 138 are at nearly the same voltage the generator telltale 20 isextinguished. If the generator 74 stops producing ap output when theignition switch 14 is in the ON setting the contacts 118 and 122 will beclosed, causing the generator telltale 20 to be energized and therebywarn of the malfunction.

The telltale network 22 includes a pair of telltales 140 and 142 and anisolating resistor 144. While the selection of the telltales 140 and 142and the isolating resistor 144 is determined by the particularapplication, the telltales 140 and 142 are typically two candlepowerunits and the resistor 144 is a ohm resistor. In the illustratedembodiment the telltale 140 is the well-known COLD telltale that isenergized through a bimetal switch 146 when the engine is cold and thelead 136 is energized by the ignition switch 14 being in the ON setting.As the engine is heated the bimetal switch 146 will open the currentpath through the COLD telltale l0 and, at an increased temperature, thebimetal switch 146 will complete a current path through a lead 148, thetelltale 142, and the lead 136 so as to energize the telltale 142, whichis the well-known HOT telltale used to indicate that the engine isoverheated, when the ignition switch 14 is in the ON setting and theengine is at the increased temperature.

The operativeness of the HOT telltale 142 is checked by placing theignition switch 14 in the ON setting when the engine is stopped. Sincethe oil pressure switch 24 is open when the engine is stopped, placingthe ignition switch 14 in the ON setting completes a current path fromthe battery 12 through the lead 52, the junction block 54, the lead 56,the contacts 40, the lead 136, the HOT telltale 142, the isolatingresistor 144, the lead 70, the lead 126, the lead 128, the contacts 112and 110, the lead 130, the lead 132, and the field winding 78. The HOTtelltale 142 is thus energized so as to check its operativeness when theengine is stopped and the ignition switch 14 is in the ON setting. TheHOT telltale 142 is extinguished when the engine operation closes theoil pressure switch 24 as the battery 12 voltage is then presentedthrough the oil pressure switch 24 and the lead 68 to the lead 70,applying the same voltage to each side of the HOT telltale 142.

As persons skilled in the art will appreciate, the operativeness ofvarious other telltales presently found in motor vehicles may be checkedin a fashion similar to that used in checking the HOT telltale 142operativeness. That is, by coupling them to the lead 70 throughresistors analogous in operation to the isolating resistor 144. In thealternative, a diode may be substituted for the isolating resistor 144.A diode so substituted would have its anode connected to the lead 148and its cathode connected to the lead 70 so as to per mit energizationof the HOT telltale 142 through the field winding 78, as was previouslyexplained, and to prevent reverse leakage currents when the oil pressureswitch 24 is closed.

The operation of the subject circuitry will now be explained. When theignition switch 14 is in the OFF setting the circuitry in FIG. 1 isdeenergized and the grounded contacts 34 and 36 on the ignition switch14 are closed.

When the ignition switch 14 is placed in the ACC setting the contacts 38are closed so as to energize the lead 66, from which a plurality ofaccessory loads may be energized through the terminals 26, 28, 30 and32. Since the engine is not in operation, the oil pressure switch 24remains open so as to preclude energization of other circuitry from thelead 66 while the ignition switch 14 is in the ACC setting.

When the ignition switch 14 is placed in the ON setting prior tostarting the engine the contacts 38 and 40 are closed so as to supplypower to the various accessories connected to the lead 66 and to checkthe operativeness of the generator telltale and the telltale network 22.Closure of the contacts 40 energizes the lead 136 through a current pathfrom the battery 12 that includes the lead 52, the junction block 54,the lead 56, the contacts 40, and the lead 136. Since the engine isinoperative the generator 74 is not producing an output and the fieldrelay 106 is thus deenergized, leaving the contacts 118 and 122 closedso as to enable the generator telltale 20 to be energized from the lead136 through a current path that includes the lead 138, the lead 134 andthe contacts 122 and 1 18.

The HOT telltale 142 is also energized from the lead 136 but through acurrent path that includes the isolating resistor 144, the lead 70, thelead 126, the lead 128, the contacts 112 and 110, the lead 130, the lead132, and the field winding 78. Of course, if other telltales in thetelltale network 22 were connected to the lead 70 in a similar fashionto the connection of the HOT telltale 142, the operativeness of thesetelltales would be checked simultaneously with the checking of the HOTtelltale 142.

Since the COLD telltale 140 is energized from the lead 136 through thebimetal switch 146 when the engine is cold, no additional provisionneeds to be made for checking its operativeness.

Placing the ignition switch 14 in the START setting closes the contacts42 so as to energize the cranking network and opens the contacts 38 soas to relieve the battery 12 of the accessory loads connected to thelead 66 when the cranking network is starting the engine. The contacts40 remain closed when the ignition switch 14 is placed in the STARTsetting so as to permit continued checking of the generator telltale 20and the telltale network 22 operativeness when starting the engine. Inaddition, placing the ignition switch 14 in the START setting closes thecontacts 44 so as to energize the starting branch 46 and the pump 10,thereby transferring fuel to the engine when starting the engine. Sincethe starting branch 46 provides a low impedance current path from thebattery 12 to the pump 10 it supplies virtually the entire battery 12voltage to the pump 10, providing it with an increased fuel transfercapability when starting the engine. In addition, a transmissioninterlock switch (not shown), with which persons skilled in the art arefamiliar, may be used to prevent cranking of the engine by the crankingnetwork until the pump 10 has supplied the engine with sufficient fuelfor starting. For example, when the well-known vehicle transmission isengaged the cranking network is disengaged, but the starting branch 46is unaffected. The battery 12 is thus protected from an excessivecurrent drain by the cranking network while the pump 10 transferssufficient fuel to the engine for starting, after which the transmissionis disengaged and the engine started.

In the event the engine becomes flooded prior to its being started thesupply of fuel to the engine may be discontinued by setting the enginethrottle for maximum engine speed so as to open the normally closedswitch 50 and deenergize the pump 10. This may be done in vehiclesemploying the well-known accelerator pedal simply by fully depressingthe accelerator pedal. Setting the engine throttle for maximum enginespeed thus facilitates starting a flooded engine since the engine can becranked by the cranking network while the fuel supply to the engine isdiscontinued.

When the engine has been started the ignition switch 14 is returned tothe ON setting, opening the contacts 44 so as to deenergize the startingbranch 46 and closing the contacts 38 so as to energize the operatingbranch 48 upon closure of the oil pressure switch 24. Energization ofthe pump 10 is continued without interruption as the oil pressure switch24 is closed almost immediately upon starting the engine. The pump 10 isenergized by the operating branch 48 in accordance with the enginethrottle setting so that when the engine throttle is set for low enginespeeds the switch 64 is opened and the pump 10 is energized through theresistor 62 and when the engine throttle is set for high engine speedsthe switch 64 is closed and the pump 10 is energized through the switch64. The switch 64 in the illustrated embodiment thus provides foroperating the pump 10 at two levels of fuel transfer capability, thoughit is recognized that use of a variable resistance in place of theswitch 64 would provide for operating the pump 10 at several additionallevels of fuel transfer capability.

Upon closure of the oil pressure switch 24 the field winding 78 isenergized through the voltage regulator assembly 76 so as to enable thegenerator 74 to produce an output. When the generator 74 is producing anoutput the voltage at the junction 131 energizes the field relay 106,which closes the contacts 120 and 122 so as to complete a current pathfrom the generator 74 output through the lead 102, the junction block54, the lead 133, the contacts 120 and 122, the lead 134, and the lead138 to the generator telltale 20. The generator telltale is thusextinguished since the leads 136 and 138 are at nearly the same voltage.1

Closure of the oil pressure switch 24 also'extinguishes the HOT telltale142 by supplying a voltage to the lead 70 that is nearly the samevoltage as is on the lead 136, as was previously explained. Of course,the COLD telltale 140 will remain energized so long as the bimetalswitch 146 completes a current path from the energized lead 136 throughthe COLD telltale 140 to ground.

In the event the engine oil pressure falls to a level insufficient toproperly lubricate the engine while the engine is in operation, the oilpressure switch 24 will open, deenergizing the field winding 78 andpermitting the energization of the generator telltale 20 and thetelltale network 22. When the field winding 78 is deenergized thegenerator 74 no longer produces an output and the field relay 106 isdeenergized so as to apply ground potential to the generator telltale 20through the contacts 118 and 122, the lead 134, and the lead 138. Sincethe lead 136 is energized, the generator telltale 20 is also energized.

In addition, opening the oil pressure switch 24 permits energization ofthe HOT telltale 142 through the lead 148, the isolating resistor 144,the lead 70, the lead 126, the lead 128, the contacts 112 and 110, thelead 130, the lead 132, and the field winding 78. Other telltalesconnected in parallel with the HOT telltale would be energized in asimilar fashion.

Several, or even all, of the telltales in the vehicle may thus beenergized simultaneously to indicate that the engine oil pressure isinsufficient to properly lubricate the engine. it is thereforeunnecessary to have a separate telltale to monitor the engine oilpressure, which is the present familiar practice. Furthermore, since'thepump 10 is energized through the oil pressure switch 24 when theignition switch 14 is in the ON setting, the simultaneous energizationof several telltales in the vehicle serve to indicate that the pump 10is deenergized and that the engine will soon stop due to a lack of fuel,the time required to stop the engine depending upon the present rate offuel consumption by the engine and the amount of fuel available to theengine.

While it is desirable that the engine be stopped soon after the oilpressure switch 24 is opened to prevent harming the engine by operationof the engine when the engine oil pressure is insufficient to properlylubricate the engine, there are certain circumstances under which thevehicle operator may wish to temporarily continue the engine operation.He may do so by placing the ignition switch 14 in the START setting soas to energize the pump 10 through the starting branch 46 as waspreviously explained thereby maintaining the supply of fuel to theengine. (Since the transmission is engaged while the vehicle is beingdriven, the cranking network will not be energized at this time.) Byhaving the ignition switch 14 spring biased to prevent its remaining inthe START setting, as is customarily the case, the vehicle operator musteither continuously or intermittently hold the ignition switch 14 in theSTART setting to provide sufficient fuel to the engine to prevent itsstoppage. The engine will thus be kept in operation so long as thevehicle operator is willing to take afi'irmative action to prevent itsstopping. The engine will stop when he permits it to run out of fuel bychanging the ignition switch 14 setting to other than the START SETTING.

When it is desired to stop the engine after normal operation theignition switch 14 is placed in the OFF setting, which closes thecontacts 34 and 36 so as to ground the circuitry shown in FIG. 1.

Some additional features are provided by the subject circuitry that havenot previously been discussed. Among these are use of the generatortelltale 20 to check the rectifier network 88 operativeness and a meansof making a vehicle employ subject circuitry less subject to theft.

The generator telltale 20 is energized when a positive rectifier 96, 98,or in the rectifier network 88 is shorted and the ignition switch 14 isin the OFF setting as shorting one of the rectifiers 96, 98, or 100 willenergize the field relay 106 so as to complete a current path throughthe generator telltale 20 and the grounded contacts 36. For example, ifthe rectifier 98 is shorted a current path is completed from the battery12 through the lead 52, junction block 54, the lead 102, the rectifier98 the winding 86, the winding 82, the junction 131 and the relaywinding 116, energizing the relay winding 116 so as to close thecontacts 120 and 122. Closure of the contacts 120 and 122 completes acurrent path from the battery 12 through the lead 52, the junction block54, the lead 133, the contacts 120 and 122, the lead 134, the lead 138,the generator telltale 20, the lead 136, and the grounded contacts 36.The generator telltale 20 is thus energized whenever one of the positiverectifiers 96, 98, or 100 in the rectifier network 88 is shorted and theignition switch 14 is in the OFF setting.

The presence of a shorted negative rectifier 90, 92, or 94 in therectifier network 88 causes the generator telltale 20 to becomeenergized when the generator 74 is being driven by the engine as ashorted negative rectifier in the rectifier network 88 precludes thevoltage at the junction 131 from energizing the relay winding 116. Therelay winding 116 is thus deenergized, closing the contacts 118 and 122so as to energize the generator telltale 20 by the battery 12 through acurrent path that includes the lead 52, the junction block 54, the lead56, the contacts 40, the lead 136, the generator telltale 20, the lead138, the lead 134, and the contacts 122 and 118. For example, when thenegative rectifier 90 is shorted the junction 131 is connected to groundso as to deenergize the relay winding 116 and permit energization of thegenerator telltale 20 through the current path just described, but inthe case of a shorted negative rectifier 92 or 94 the junction 13] isnot grounded. The generator telltale 20 will thus remain deenergized solong as the generator 74 output maintains the relay winding 116energized. However, once the engine has been stopped and restarted ashorted negative rectifier 92 or 94 will prevent the generator 74 fromproducing its normal output. The voltage at the junction 131 is thusprevented from building up sufficiently to energize the relay winding116 and the generator telltale 20 will be energized when the ignitionswitch 14 is in the ON setting as was previously explained. It can beseen from the foregoing that shorting one of the negative rectifiers 90,92 or 94 in the rectifier network 88 before the engine is started willbe indicated when the engine is in operation and the shorting of therectifier 90 can be detected even if it occurs while the engine is inoperation.

A vehicle employing the subject circuitry may be made less subject totheft than vehicles employing conventional circuitry as the groundedcontact 34 in the subject circuitry grounds the pump 10 when theignition switch 14 is in the OFF setting. While a vehicle which employsan electric fuel pump is inherently more difficult to steal because ofthe additional electric circuit that must be jumpered, the groundedcontact 34 provides an additional measure of security as the extremelyreliable circuitry in the pump energization network 16 and the pump 10may be positioned in a very inaccessible location. The inaccessibilityof these elements is an additional deterrent to jumpering" and as suchthe vehicle is made more theftproof.

While the foregoing description has been keyed to the illustratedembodiment, it is to be understood that other embodiments may be used topractice the present invention and that the present invention is to belimited only by the following claims.

Iclaim:

1. Circuitry for a motor vehicle having a throttle controlled engine anda reservoir for fuel, the circuitry comprising, in combination, anelectric fuel pump for transferring fuel between the reservoir and theengine; a power source for energizing the pump; and a pump energizationnetwork for controlling the energization of the pump by the power sourcein accordance with the engine operation, the pump energization networkincluding an operating branch for energizing the pump from the powersource when the engine is in operation, the operating branch including aresistor in series with the pump and the power source for reducing thepower supplied to the pump by the power source so as to establish a lowfuel transfer capability of the pump when the engine throttle is set tooperate the engine at low speeds and a switch responsive to the enginethrottle setting for increasing the power supplied to the pump by thepower source by completing a low impedance current path from the powersource to the pump so as to increase the fuel transfer capability of thepump when the engine throttle is set to operate the engine at highspeeds.

2. Circuitry for a motor vehicle having a throttle controlled engine anda reservoir for fuel, the circuitry comprising, in combination, anelectric fuel pump for transferring fuel between the reservoir and theengine; a power source for energizing the pump; a pump energizationnetwork for controlling the energization of the pump by the power sourcein accordance with the engine operation, the pump energization networkincluding an operating branch for energizing the pump from the powersource when the engine is in operation, the operating branch including aresistor in series with the pump and the power source for reducing thepower supplied to the pump by the power source so as to establish a lowfuel transfer capability of the pump when the engine throttle is set tooperate the engine at low speeds and a switch responsive to the enginethrottle setting for increasing the power supplied to the pump by thepower source by completing a low impedance current path from the powersource to the pump so as to increase the fuel transfer capability of thepump when the engine throttle is set to operate the engine at highspeeds; and an engine responsive switch for controlling the energizationof the operating branch and the pump by the power source in accordancewith the engine operation so as to energize the operating branch and thepump when the engine is in operation.

3. Circuitry for a motor vehicle having a throttle controlled engine anda reservoir for fuel, the circuitry comprising, in combination, anelectric fuel pump for transferring fuel between thereservoir and theengine; a power source for energizing the pump; a plural setting enginecontrolling switch including an engine On setting; and a pumpenergization network for controlling the energization of the pump by thepower source in accordance with the engine operation and the setting ofthe engine controlling switch, the pump energization network includingan operating branch for energizing the pump from the power source whenthe engine controlling switch is in the engine On setting and the engineis in operation, the operating branch including a resistor in serieswith the pump and the power source for reducing the power supplied tothe pump by the power source so as to establish a low fuel capability ofthe pump when the engine throttle is set to operate the engine at lowspeeds and a switch responsive to the engine throttle setting forincreasing the power supplied to the pump by the power source bycompleting a low impedance current path from the power source to thepump so as to increase the fuel transfer capability of the pump when theengine throttle is set to operate the engine at high speeds.

4. Circuitry for a motor vehicle having a throttle controlled engine anda reservoir for fuel, the circuitry comprising, in combination, anelectric fuel pump for transferring fuel between the reservoir and theengine; a power source for energizing the pump; a plural setting enginecontrolling switch including an engine On setting; a pump energizationnetwork for controlling the energization of the pump by the power sourcein accordance with the engine operation and the setting of the enginecontrolling switch, the pump energization network including an operatingbranch for energizing the pump from the power source when the enginecontrolling switch is in the engine On setting and the engine is inoperation, the operating branch including a resistor in series with thepump and the power source for reducing the power supplied to the pump bythe power source so as to establish a low fuel transfer capability ofthe pump when the engine throttle is set to operate the engine at lowspeeds and a switch responsive to the engine throttle setting forincreasing the power supplied to the pump by completing a low impedancecurrent path from the power source to the pump so as to increase thefuel transfer capability of the pump when the engine throttle is set tooperate the engine at high speeds; and an engine responsive switch forcontrolling the energization of the operating branch in accordance withthe engine operation so as to energize the operating branch and the pumpwhen the engine is in operation and the engine controlling switch is inthe engine 0n setting.

5. Circuitry for a motor vehicle having a throttle controlled engine anda reservoir for fuel, the circuitry comprising, in combination, anelectric fuel pump for transferring fuel between the reservoir and theengine; a power source for energizing the pump; and a pump energizationnetwork for controlling the energization of the pump by the powersource, the pump energization network including a starting branch forenergizing the pump from the power source when the engine is beingstarted, the starting branch including a switch responsive to the enginethrottle setting for preventing energization of the starting branch andthe pump when the engine is being started and the engine throttle is setto operate the engine at maximum speed so as to facilitate starting theengine by preventing the pump from transferring fuel to the engine whenthe engine is flooded.

6. Circuitry for a motor vehicle having a throttle controlled engine anda reservoir for fuel, the circuitry comprising, in combination, anelectric fuel pump for transferring fuel between the reservoir and theengine; a power source for energizing the pump; a plural setting enginecontrolling switch including an engine Starting setting; and a pumpenergization network for controlling the energization of the pump by thepower source in accordance with the setting of the engine controllingswitch, the pump energization network including a starting branch forenergizing the pump from the power source when the engine controllingswitch is in the engine Starting setting, the starting branch includinga switch responsive to the engine throttle setting for preventingenergization of the pump when the engine controlling switch is in theengine Starting setting and the engine throttle is set to operate theengine at maximum speed so as to facilitate starting the engine bypreventing the pump from transferring fuel to the engine when the engineis flooded.

7. Circuitry for a motor vehicle having a throttle controlled engine anda reservoir for fuel, the circuitry comprising, in combination, anelectric fuel pump for transferring fuel between the reservoir and theengine; a power source for energizing the pump; a plural setting enginecontrolling switch including engine On and engine Starting settings; anda pump energization network for controlling the energization of the pumpby the power source in accordance with the setting of the enginecontrolling switch, the pump energization network including a startingbranch for energizing the pump from the power source when the enginecontrolling switch is in the engine Starting setting, the startingbranch including a first switch responsive to the engine throttlesetting for preventing energization of the pump when the enginecontrolling switch is in the engine Starting setting and the enginethrottle is set to operate the engine at maximum speed so as tofacilitate starting the engine by preventing the pump from transferringfuel to the engine when the engine is flooded, and an operating branchfor energizing the pump from the power source when the enginecontrolling switch is in the engine On setting, the operating branchincluding a resistor in series with the pump 1 and the power source forreducing the power supplied to the pump by the power source so as toestablish a low fuel transfer capability of the pump when the enginethrottle is set to operate the engine at low speeds and a second switchresponsive to the engine throttle setting for increasing the powersupplied to the pump by completing a low impedance current path from thepower source to the pump so as to increase the fuel transfer capabilityof the pump when the engine throttle is set to operate the engine athigh speeds.

8. Circuitry for a motor vehicle having an engine and a reservoir forfuel, the circuitry comprising, in combination, an electric fuel pumpfor transferring fuel between the reservoir and the engine; a powersource for energizing the pump; a plural setting engine controllingswitch including engine On and engine Starting settings; a pumpenergization network for controlling the energization of the pump by thepower source in accordance with the setting of the engine controllingswitch and the engine operation, the pump energization network includinga starting branch for energizing the pump from the power source when theengine controlling switch is in the engine Starting setting and anoperating branch for energizing the pump from the power source when theengine controlling switch is in the engine On setting and the engine isin operation; and an engine responsive switch responsive to the engineoil pressure for controlling the energization of the operating branch inaccordance with the engine oil pressure so as to deenergize theoperatingbranch and the pump when the engine oil pressure isinsufficient to properly lubricate the engine and the engine controllingswitch is in the engine On setting.

9. Circuitry for a motor vehicle having a throttle controlled engine anda reservoir for fuel, the circuitry comprising, in combination, anelectric fuel pump for transferring fuel between the reservoir and theengine; a power source for energizing the pump; a plural setting enginecontrolling switch including engine On and engine Starting settings; apump energization network for controlling the energization of the pumpby the power source in accordance with the setting of the enginecontrolling switch and the engine operation, the pump energizationnetwork including a starting branch for-energizing the pump from thepower source when the engine controlling switch is in the engineStarting setting, the starting branch including a first switchresponsive to the engine throttle setting for preventing energization ofthe pump when the engine controlling switch is in the engine Startingsetting and the engine throttle is set to operate the engine at maximumspeed so as to facilitate starting the engine by preventing the pumpfrom transferring fuel to the engine when the engine is flooded, and anoperating branch for energizing the pump from the power source when theengine controlling switch is in the engine On setting, the operatingbranch including a resistor in series with the pump and the power sourcefor reducing the power supplied to the pump by the power source so as toestablish a low fuel transfer capability of the pump when the enginethrottle is set to operate the engine at low speeds and a second switchresponsive to the engine throttle setting for increasing the powersupplied to the pump by completing a low impedance current path from thepower source to the pump so as to increase the fuel transfer capabilityof the pump when the engine throttle is set to operate the engine athigh speeds; and an engine responsive switch responsive to the engineoil pressure for controlling the energization of the operating branch inaccordance with the engine oil pressure so as to deenergize theoperating branch and the pump when the engine oil pressure isinsufficient to properly lubricate the engine and the engine controllingswitch is in the engine On setting.

10. Circuitry for a motor vehicle having an engine and a reservoir forfuel, the circuitry comprising, in combination, supplied electric fuelpump for transferring fuel between the reservoir and the engine; a powersource for energizing the pump; a plural setting engine controllingswitch including engine On and engine Starting settings; a pumpenergization network for controlling the energization of the pump by thepower source in accordance with the setting of the engine controllingswitch and the engine operation, the pump energization network includinga starting branch for energizing the pump from the power source when theengine controlling switch is in the engine Starting setting and anoperating branch for energizing the pump from the power source when theengine controlling switch is in the engine 0n setting and the engine isin operation; a telltale network energized by the power source formonitoring at least one condition in the vehicle; and an engineresponsive switch responsive to the engine oil pressure for controllingthe energization of the operating branch and the telltale network so asto permit energization of the telltale network and to precludeenergization of the operating branch when the engine oil pressure isinsufficient to properly lubricate the engine and the engine controllingswitch is in the engine On setting, the energization of the telltalenetwork thereby indicating both that the engine oil pressure isinsufficient to properly lubricate the engine and that the engine willsoon stop due to a lack of fuel caused by deenergization of the pumpunless the pump energization is maintained by placing the enginecontrolling switch in the engine Starting setting so as to energize thepump through the starting branch.

11. Circuitry for a motor vehicle having an engine and a reservoir forfuel, the circuitry comprising, in combination, an electric fuel pumpfor transferring fuel between the reservoir and the engine; a powersource for energizing the pump; a plural setting engine controllingswitch, the engine controlling switch including an engine Off settingand a grounded contact; a pump energization network for controlling theenergization of the pump by the power source in accordance with thesetting of the engine controlling switch, the pump energization networkbeing connected to ground by the grounded contact when the enginecontrolling switch is in the engine Off setting so as to precludeoperation of the pump until the engine controlling switch setting ischanged to a setting other than the engine Off setting.

12. Circuitry for a motor vehicle comprising, in combination, a powersource; an engine driven generator for recharging the power source, thegenerator including a field winding energized by the power source forcontrolling the generator output; a voltage regulator assembly forregulating the generator output by controlling the energization of thefield winding by the power source in accordance with the generatoroutput; and an engine responsive switch for controlling the supply ofpower to the voltage regulator assembly from the power source inaccordance with the engine operation so as to preclude energization ofthe field winding when the engine is inoperative.

l3. Circuitry for a motor vehicle comprising, in combination, a powersource; an engine driven generator for recharging the power source, thegenerator including a field winding energized by the power source forcontrolling the generator output; a voltage regulator assembly forregulating the generator output by controlling the energization of thefield winding by the power source in accordance with the generatoroutput; a telltale network energized by the power source for monitoringat least one condition in the vehicle other than the generatoroperation; and an engine responsive switch both for controlling thesupply of power from the power source to the voltage regulator assemblyso as to energize the field winding in accordance with the engineoperation, the engine responsive switch precluding energization of thefield winding when the engine is inoperative, and also for controllingthe energization of the telltale network so as to permit energization ofthe telltale network through the field winding when the engine isinoperative and to preclude energization of the telltale network throughthe field winding when the engine is operative, the energization of thetelltale network when the engine is inoperative providing a check of thetelltale network operativeness.

14. Circuitry for a motor vehicle comprising, in combination, a powersource; an engine driven generator for recharging the power source, thegenerator including a field winding energized by the power source forcontrolling the generator output; a voltage regulator assembly forregulating the generator output by controlling the energization of thefield winding by the power source, the voltage regulator assemblyincluding a voltage regulator for sensing the generator output and forcontrolling the energization of the field winding in accordance with thegenerator output; and an engine responsive switch for controlling thesupply of power to the voltage regulator assembly from the power sourcein accordance with the engine operation so as to preclude energizationof the field winding when the engine is inoperative.

l5. Circuitry for a motor vehicle comprising, in combination, a powersource; an engine driven generator for recharging the power source, thegenerator including a field winding energized by the power source forcontrolling the generator output; a voltage regulator assembly forregulating the generator output by controlling the energization of thefield winding by the power source, the voltage regulator assemblyincluding a voltage regulator for sensing the generator output and forcontrolling the energization of the field winding in accordance with thegenerator output and a field relay for sensing the presence of agenerator output and for supplying the generator output to the voltageregulator when the generator is producing an output; a telltale networkenergized by the power source for monitoring at least one condition inthe vehicle other than the generator operation; and an engine responsiveswitch both for controlling the supply of power from the power source tothe voltage regulator assembly so as to energize the field winding inaccordance with the engine operation, the engine responsive switchprecluding energization of the field winding when the engine isinoperative, and also for controlling the energization of the telltalenetwork so as to permit energization of the telltale network through thefield winding when the engine is inoperative and to precludeenergization of the telltale network through the field winding when theengine is operative, the energization of the telltale network when theengine is inoperative providing a check of the telltale networkoperativeness.

l6. Circuitry for a motor vehicle comprising, in combination, a powersource; an engine driven generator for recharging the power source, thegenerator including a field winding energized by the power source forcontrolling the generator output, a voltage regulator assembly forregulating the generator output by controlling the energization of thefield winding by the. power source in accordance with the generatoroutput; a telltale network energized by the power source for monitoringat least one condition in the vehicle other than the generatoroperation; and an engine responsive switch responsive to the engine oilpressure both for controlling the supply of power from the power sourceto the voltage regulator assembly so as to energize the field winding inaccordance with the engine operation, the engine responsive switchprecluding energization of the field winding when the engine bilpressure is insufficient to properly lubricate the engine, and also forcontrolling the energization of the telltale network so as to permitenergization of the telltale network through the field winding when theengine oil pressure is insufficient to properly lubricate the engine andto preclude energization of the telltale network through the fieldwinding when the engine oil pressure is sufficient to properly lubricatethe engine, the energization of the telltale network when the engine isnot in operation providing a check of the telltale network operativenessand the energization of the telltale network when the engine is inoperation providing an indication that the engine oil pressure isinsufficient to properly lubricate the engine.

17. Circuitry for an engine driven motor vehicle comprising, incombination, a power source; a plural setting engine controlling switchincluding engine On, engine Off, and engine Starting settings, theengine controlling switch also including a grounded contact; an enginedriven AC generator for recharging the power source, the generatorincluding a field winding energized by the power source for controllingthe generator output and a rectifier network for rectifying thegenerator output so as to facilitate recharging the power source, therectifier network including positive rectifiers; a voltage regulatorassembly for regulating the generator output by controlling theenergization of the field winding by the power source, the voltageregulator assembly including a voltage regulator for sensing thegenerator output and for controlling the energization of the fieldwinding in accordance with the generator output and a field relay forsensing the presence of a generator output and for supplying thegenerator output to the voltage regulator when the generator isproducing an output, the field relay being energized by the generatoroutput when the generator is producing an output and by the power sourcewhen a positive rectifier in the rectifier network is short circuitedand the generator is not producing an output; and a generator telltaleenergized by the power source in accordance with the energization of thefield relay and the setting of the engine controlling switch, thegenerator telltale being energized when the field relay is deenergizedand the engine controlling switch is in the engine On or engine Startingsetting so as to provide an indication that the generator isinoperative, the generator telltale also being energized through thegrounded contact when the field relay is energized by the power sourcethrough a shorted positive rectifier and the engine controlling switchis in the engine Off setting so as to provide an indication of therectifier network operativeness.

l8. Circuitry for a motor vehicle having an engine and a reservoir forfuel, the circuitry comprising, in combination, an electric fuel pumpfor transferring fuel between the reservoir and the engine; a powersource for energizing the pump; a plural setting engine controllingswitch including engine On and engine Starting settings; a pumpenergization network for controlling the energization of the pump by thepower source in accordance with the engine operation and the setting ofthe engine controlling switch, the pump energization network including astarting branch for energizing the pump from the power source when theengine controlling switch is in the engine Starting setting and anoperating branch for energizing the pump from the power source when theengine controlling switch is in the engine On setting and the engine isin operation; an engine driven generator for recharging the powersource, the generator including a field winding energized by the powersource for controlling the generator output; a voltage regulatorassembly for regulating the generator output by controlling theenergization of the field winding by the power source in accordance withthe generator output; a telltale network energized by the power sourcefor monitoring at least one condition in the vehicle other than thegenerator operation; and an engine responsive switch responsive to theengine oil pressure for controlling the energization of the operatingbranch in accordance with the engine oil pressure so as to deenergizethe operating branch and the pump when the engine oil pressure isinsufficient to properly lubricate the engine and the engine controllingswitch is in the engine On setting, for controlling the supply of powerfrom the power source to the voltage regulator assembly so as toenergize the field winding in accordance with the engine operation, theengine responsive switch permitting energization of the field windingwhen the engine oil pressure is sufficient to properly lubricate theengine and precluding energization of the field winding when the engineoil pressure is insufficient to properly lubricate the engine, and forcontrolling the energization of the telltale network so as to permitenergization of the telltale network through the field winding when theengine oil pressure is insufficient to properly lubricate the engine andto preclude energization of the telltale network through the fieldwinding when the engine oil pressure is sufficient to properly lubricatethe engine, the energization of the telltale network when the engine isnot in operation providing a check of the telltale network operativenessand the energization of the telltale network when the engine is inoperation providing an indication that the engine oil pressure isinsufficient to properly lubricate the engine and that the engine willsoon stop due to a lack of fuel caused by deenergization of the pumpunless the pump energization is maintained by placing the enginecontrolling switch in the engine Starting setting so as to energize thepump through the starting branch.

19. Circuitry for a motor vehicle having an engine and a reservoir forfuel, the circuitry comprising, in combination, an electric fuel pumpfor transferring fuel between the reservoir and the engine; a powersource for energizing the pump; a plural setting engine controllingswitch including engine On, engine Off, and engine Starting settings,the engine controlling switch also including a grounded contact; a pumpenergization network for controlling the energization of the pump by thepower source in accordance with the engine operation and the setting ofthe engine controlling switch, the pump energization network beingconnected to ground by the grounded contact when the engine controllingswitch is in the engine Off setting so as to preclude operation of thepump until the engine controlling switch sett'ing is changed to asetting other than the engine Off setting, the pump energization networkincluding a starting branch for energizing the pump from the powersource when the engine controlling switch is in the engine Startingsetting and an operating branch for energizing the pump from the powersource when the engine controlling switch is in the engine On settingand the engine is in operation; an engine driven AC generator forrecharging the power source, the generator including a field windingenergized by the power source for controlling the generator output and arectifier network for rectifying the generator output so as tofacilitate recharging the power source, the rectifier network includingpositive rectifiers; a voltage regulator assembly for sensing thegenerator output and for regulating the generator output by controllingthe energization of the field winding by the power source in accordancewith the generator output; a generator telltale energized by the powersource in accordance with the generator output and the setting of theengine controlling switch, the generator telltale being energized whenthe engine controlling switch is in the engine On or engine Startingsetting and the voltage regulator assembly senses that the generator isnot producing an output so as to provide an indication that thegenerator is inoperative and being energized through the groundedcontact when the power source supplies power to the voltage regulatorassembly through a shorted positive rectifier and the engine controllingswitch is in the engine Off setting so as to provide an indication ofthe rectifier network operativeness; a telltale network energized by thepower source for monitoring at least one condition in the vehicle otherthan the generator operation; and an engine responsive switch responsiveto the engine oil pressure for controlling the energization of theoperating branch in accordanc'e with the engine oil pressure so as todeenergize the operating branch and the pump when the engine oilpressure is insufficient to properly lubricate the engine and the enginecontrolling switch is in the engine On setting, for controlling thesupply of power from the power source to the voltage regulator assemblyso as to energize the field winding in accordance with the engineoperation, the engine responsive switch permitting energization of thefield winding when the engine oil pressure is sufficient to properlylubricate the engine and precluding energization of the field windingwhen the engine oil pressure is insufi'icient to properly lubricate theengine, and for controlling the energization of the telltale network soas to permit energization of the telltale network through the fieldwinding when the engine oil pressure is insufficient to properlylubricate the engine and to preclude energization of the telltalenetwork through the field winding when the engine oil pressure issufficient to properly lubricate the engine, the energization of thetelltale network when the engine is not in operation providing a checkof the telltale network operativeness and the energization of thetelltale network when the engine is'in operation providing an indicationthat the engine oil-pressure is insufficient to properly lubricate theengine and that the engine will soon stop due to a lack of fuel causedby deenergization of the pump unless the pump energization is maintainedby placing the engine controlling switch in the engine Starting settingso as to energize the pump through the starting branch.

20. Circuitry for a motor vehicle having a throttle controlled engineand a reservoir for fuel, the circuitry comprising, in combination, anelectric fuel pump for transferring fuel between the reservoir and theengine; a power source for energizing the pump; a plural setting enginecontrolling switch including engine On, engine Off, and engine Startingsettings, the engine controlling switch also including a groundedcontact; a pump energization network for controlling the energization ofthe pump by the povfe'r source in accordance with the engine operationand the setting of the engine controlling switch, the pump energizationnetwork being connected to ground by the grounded contact when theengine controlling switch is in the engine Off setting so as to precludeoperation of the pump until the engine controlling switch setting ischanged to a setting other than the engine Off setting, the pumpenergization network including a starting branch for energizing the pumpfrom the power source when the engine controlling switch is in theengine Starting setting, the starting branch including a first switchresponsive to the engine throttle setting for preventing energization ofthe pump when the engine controlling switch is in the engine Startingsetting and the engine throttle is set to operate the engine sourcemaximum speed so as to facilitate starting the engine by preventing thepump from transferring fuel to the engine when the engine is flooded,and an operating branch for energizing the pump from the power sourcewhen the engine controlling switch is in the engine On setting and theengine is in operation, the operating branch including a resistor inseries with the pump and the power source for reducing the powersupplied to the pump by the power source so as to establish a low fueltransfer capability of the pump when the engine throttle is set tooperate the engine at low speeds and a second switch responsive to theengine throttle setting for increasing the power supplied to the pump bycompleting a low impedance current path from the power source to thepump so as to increase the fuel transfer capability of the pump when theengine throttle is set to operate the engine at high speeds; an enginedriven AC generator for recharging the power source, the generatorincluding a field winding energized by the power source for controllingthe generator output and a rectifier network for rectifying thegenerator output so as to facilitate recharging the power source, therectifier network including positive rectifiers; a voltage regulatorassembly for regulating the generator output by controlling theenergization of the field winding by the power source, the voltageregulator assembly including a voltage regulator for sensing thegenerator output and for controlling the energization of the fieldwinding in accordance with the generator output and a field relay forsensing the presence of a generator output and for supplying thegenerator output to the voltage regulator when the generator isproducing an output, the field relay being energized by the generatoroutput when the generator is producing an output and by the power sourcewhen a positive rectifier in the rectifier network is short circuitedand the generator is not producing an output; a generator telltaleenergized by the power source in accordance with the energization of thefield relay and the setting of the engine controlling switch, thegenerator telltale being energized when the field relay is deenergizedand the engine controlling switch is in the engine On or engine Startingsetting so as to provide an indication that the generator isinoperative, the generator telltale also being energized through thegrounded contact when the field relay is energized by the power sourcethrough a shorted positive rectifier and the engine controlling switchis in the engine Off setting so as to provide an indication of therectifier network operativeness; a telltale network energized by thepower source for monitoring at least one condition in the vehicle otherthan the generator operation; and an engine responsive switch responsiveto the engine oil pressure for controlling the energization of theoperating branch in accordance with the engine oil pressure so as todeenergize the operating branch and the pump when the engine oilpressure is insufi'icient to properly lubricate the engine and theengine controlling switch is in the engine n setting, for controllingthe supply of power from the power source to the voltage regulatorassembly so as to energize the field winding in accordance with theengine operation, the engine responsive switch permitting energizationof the field winding when the engine oil pressure is sufficient toproperly lubricate the engine and precluding energization of the fieldwinding when the engine oil pressure is insufficient to properlylubricate the engine, and for controlling the energization of thetelltale network so as to permit energization of the telltale networkthrough the field winding when the engine oil pressure is insufficientto properly lubricate the engine and to preclude energization of thetell- 18 tale network through the field winding when the engine oilpressure is sufficient to properly lubricate the engine, theenergization of the telltale network when the engine is not in operationproviding a check of the telltale network operativeness and theenergization of the telltale network when the engine is in operationproviding an indication that the engine oil pressure is insufficient toproperly lubricate the engine and that the engine will soon stop due toa lack of fuel caused by deenergization of the pump unless the pumpenergization is maintained by placing the engine controlling switch inthe engine Starting setting so as to energize the pump through thestarting branch P0405) UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3,587,545 Dated September 7, 1971 Inventor(s)Richard P. Ballou It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

q r- In the Specification, Column 3, line 27 "generator" should readdelcotron Column 5, line l9 "10" should read 140 Column 9, line 61,after "fuel" insert transfer Column 11, line 70, delete "supplied" andinsert an Column 16, line 25,

delete "source" and insert at Signed and sealed this 8th day of February1972.

(SEAL) Attest:

EDWARD M.FLE'I'CHER,JR. ROBERT GOTTSCHALK Attestlng Officer Commissionerof Patents

